Recommendations of the Advisory Committee on Immunization Practices (ACIP)

Summary

This report provides information regarding the modestly increased risk
for meningococcal disease among college freshmen, particularly those who live
in dormitories or residence halls. It presents recommendations developed by
the Advisory Committee on Immunization Practices regarding the education
of students and parents about meningococcal disease and the
polysaccharide meningococcal vaccine so that they can make informed decisions
regarding vaccination.

INTRODUCTION

Neisseria meningitidis causes both sporadic disease and outbreaks. As a result
of the control of Haemophilus influenzae type b infections,
N. meningitidis has become the leading cause of bacterial meningitis in children and young adults in the
United States (1). Outbreaks of meningococcal disease were rare in the United States in
the 1980s; however, since 1991, the frequency of localized outbreaks has increased
(2). From July 1994 through July 1997, 42 meningococcal outbreaks were reported, four
of which occurred at colleges (3). However, outbreaks continue to represent <3% of
total U.S. cases (3).

Rates of meningococcal disease remain highest for infants, but in the past
decade, rates have increased among adolescents and young adults
(4). During 1994--1998, approximately two thirds of cases among persons aged 18--23 years were caused
by serogroups C, Y, or W135 and therefore were potentially preventable with
available vaccines (5) (CDC, unpublished data) (Figure 1). Although the quadrivalent
meningococcal polysaccharide vaccine is safe and efficacious
(5,6), decisions about who to target for vaccination require understanding of the groups at risk, the burden of
disease, and the potential benefits of vaccination.

New data are available regarding the risk for meningococcal disease in college
students. This report reviews these data and provides medical professionals with
guidelines concerning meningococcal disease and college students.

BACKGROUND

Meningococcal Disease in the Military

Military recruits and college freshmen have several common characteristics
(e.g., age, diverse geographic backgrounds, and crowded living conditions). Therefore,
data obtained from recruits have been used to evaluate meningococcal disease and
vaccine among college freshmen.

Before 1971, rates of meningococcal disease were elevated among U.S.
military recruits. Outbreaks frequently followed large-scale mobilizations, and recruits in
their initial training camps were at substantially greater risk for disease than were
regular troops (7). Military recruits enter military service for the first time at a few large
U.S. military recruit training centers. After 8--12 weeks of initial training, they disperse
to perform their military service at many different locations. During mobilization for
the Vietnam conflict, outbreaks of meningococcal disease at training camps involving
substantial numbers of recruits were caused by sulfadiazine-resistant strains of
N. meningitidis. During 1964--1970, the rate of hospitalizations resulting from
meningococcal disease among all active duty service members was 25.2 per 100,000
person- years (LTC Frederick Erdtmann, MD, MPH, Office of the Surgeon General, U.S.
Army, briefing, 1981). These circumstances led to development of meningococcal
polysaccharide vaccines (8). Field trials of group C polysaccharide vaccine among U.S.
Army recruits demonstrated an 89.5% reduction in the rate of serogroup C
meningococcal disease among vaccinated versus nonvaccinated recruits
(9,10); thus, beginning in October 1971, all new recruits were vaccinated with the group C vaccine
(11), and by Fall 1982, all recruits were receiving the quadrivalent polysaccharide vaccine
(7). However, rates of meningococcal disease in U.S. Army personnel declined before the
1971 vaccination campaigns (7), suggesting that smaller recruit populations at training
installations and the natural periodicity of outbreaks may have contributed to the
decline in disease.

Rates of meningococcal disease remain low in the military, and large outbreaks
no longer occur. Since 1990, records of all hospitalizations of active duty service
members in military hospitals worldwide have been integrated with military personnel records
in the Defense Medical Surveillance System (DMSS). During 1990--1998, the overall
rate of hospitalizations from meningococcal disease among enlisted, active-duty
service
members was 0.51 per 100,000 person-years (J. Brundage, DMSS Army Medical
Surveillance Activity, personal communication).

Approximately 180,000 military recruits receive a single dose of
quadrivalent polysaccharide meningococcal vaccine annually. Revaccination is only indicated
when military personnel are traveling to countries in which
N. meningitidis is hyperendemic or epidemic (D. Trump, personal communication).

Before 1999, students reporting to two of the U.S. military academies routinely
received meningococcal vaccine. Last year, the other academies initiated
meningococcal vaccine programs.

MENINGOCOCCAL DISEASE AND COLLEGE STUDENTS

Four recent studies provide data concerning the risk for sporadic
meningococcal disease among college students (Table 1)
(12--15). The earliest of these studies was conducted during the 1990--1991 and 1991--1992 school years. A questionnaire
designed to evaluate risk factors for meningococcal disease among college students
was sent to 1,900 universities, resulting in a 38% response rate
(12). Forty-three cases of meningococcal disease were reported during the 2 years from colleges with a
total enrollment of 4,393,744 students, for a low overall incidence of 1.0 per 100,000
population per year. However, cases of meningococcal disease occurred 9--23 times
more frequently in students residing in dormitories than in those residing in other types
of accommodations. The low response rate and the inability of the study to control
for
other risk factors (e.g., freshman status) make these results difficult to interpret.

In a retrospective, cohort study conducted in Maryland for the period 1992--1997,
67 cases of meningococcal disease among persons aged 1630 years were identified
by active, laboratory-based surveillance
(13). Of those cases, 14 were among
students attending Maryland colleges, and 11 were among those in 4-year colleges. The
overall incidence of meningococcal disease in Maryland college students was similar to
the incidence in the U.S. population of persons the same age (1.74/100,000 vs.
1.44/100,000, respectively); however, rates of disease were elevated among students living in
dormitories compared with students living off-campus (3.2/100,000 vs. 0.96/100,000, p=0.05).

U.S. surveillance for meningococcal disease in college students was initiated in
1998; from September 1998 through August 1999, 90 cases of meningococcal disease
were reported to CDC (14). These cases represent approximately 3% of the total cases
of meningococcal disease that occur each year in the United States. Eighty-seven
(97%) cases occurred in undergraduate students, and 40 (44%) occurred among the 2.27
million freshman students entering college each year
(16). Among undergraduates, of the 71 (82%) isolates for which serogroup information was available, 35 (49%)
were serogroup C, 17 (24%) were serogroup B, 15 (21%) were serogroup Y, and one (1%)
was serogroup W-135. Eight (9%) students died. Of the five students who died for
whom serogroup information was available, four had serogroup C isolates and one
had serogroup Y.

U.S. surveillance data from the 1998--1999 school year suggest that the overall
rate of meningococcal disease among undergraduate college students is lower than
the rate among persons aged 18--23 years who are not enrolled in college (Table 2) (0.7
vs. 1.5/100,000, respectively) (14,16). However, rates were higher among specific
subgroups of college students. Among the approximately 590,000 freshmen who live
in dormitories (17), the rate of meningococcal disease was 4.6/100,000, higher than
any age group in the population other than children aged <2 years, but lower than
the threshold of 10/100,000 recommended for initiating meningococcal vaccination
cam
paigns (6).

Of 90 students who had meningococcal disease attending college during the
1998-1999 school year, 50 were enrolled in a case-control study and matched to 148
controls by school, sex, and undergraduate vs. graduate status
(14). In a multivariable analysis, freshmen living in dormitories were at higher risk for meningococcal disease. In
addition, white race, radiator heat, and recent upper respiratory infection were
associated with disease.

In contrast to the United States, overall rates of meningococcal disease in the
United Kingdom are higher among university students compared with non-students of
similar age (15). From September 1994 through March 1997, university students had an
increased annual rate of meningococcal disease (13.2/100,000) compared with
non-students of similar age in the same health districts (5.5/100,000) and in those health
districts without universities (3.7/100,000). As in the United States, regression
analysis revealed that "catered hall accommodations," the U.K. equivalent of dormitories,
were the main risk factor. Higher rates of disease were observed at universities
providing catered hall accommodations for >10% of their student population compared with
those providing such housing for <10% of students (15.3/100,000 vs. 5.9/100,000). The
increased rate of disease among university students has prompted the United
Kingdom to initiate routine vaccination of incoming university students with a bivalent
A/C polysaccharide vaccine as part of a new vaccination program (see
MMWR 2000; Vol.49, No. RR-6 which can be referenced in the pages preceding this report)
(18).

MENINGOCOCCAL VACCINE AND COLLEGE STUDENTS

On September 30, 1997, the American College Health Association (ACHA),
which represents about half of colleges that have student health services, released a
statement recommending that "college health services [take] a more proactive role in
alerting students and their parents about the dangers of meningococcal disease," that
"college students consider vaccination against potentially fatal meningococcal
disease," and that "colleges and universities ensure all students have access to a
vaccination program for those who want to be vaccinated" (Dr. MarJeanne Collins, Chairman,
ACHA Vaccine Preventable Diseases Task Force, personal communication). Parent and
college student advocates have also encouraged more widespread use of
meningococcal vaccine in college students. In a joint study by ACHA and CDC, surveys were sent
to 1,200 ACHA-member schools; of 691 responding schools, 57 (8%) reported that
pre-exposure meningococcal vaccination campaigns had been conducted on their
campus since September 1997. A median of 32 students were vaccinated at each school
(range: 1--2,300) (J. Capparella, unpublished data). During the 1998--1999 school year,
3%--5% of 148 students enrolled in a case-control study reported receiving prophylactic
meningococcal vaccination (14). Before the 1999 fall semester, many schools mailed
information packets to incoming freshmen; data are not yet available regarding the
proportion of students who have been vaccinated.

Cost-effectiveness of meningococcal vaccine in
college students

From a societal perspective, the economic costs and benefits of vaccinating a)
a cohort of 591,587 freshmen who live in dormitories and b) all freshman enrolled in
U.S.
colleges, regardless of housing status (n=2.4 million) were evaluated, assuming
the benefits of vaccination would last 4 years (Scott et al, unpublished data). Best
and worst case scenarios were evaluated by varying cost of vaccine and
administration (range: $54--$88), costs per hospitalization ($10,924--$24,030), value of premature
death based on lifetime productivity ($1.3--$4.8 million), cost of side effects of vaccine
per case ($3,500--$12,270 per one million doses), and average cost of treating a case
of sequelae ($0--$1,476). Vaccination coverage (60% and 100%) and vaccine efficacy
(80% and 90%) were also varied for evaluation purposes.

Vaccination of freshmen who live in dormitories would result in the
administration of approximately 300,00--500,000 doses of vaccine each year, preventing 15--30
cases of meningococcal disease and one to three deaths each year. The cost per case
prevented would be $600,000--$1.8 million, at a cost per death prevented of $7 million
to $20 million.

Vaccination of all freshman would result in the administration of approximately
1.4--2.3 million doses of vaccine each year, preventing 37--69 cases of meningococcal
disease and two to four deaths caused by meningococcal disease each year. The cost
per case prevented would be $1.4--2.9 million, at a cost per death prevented of $22
million to $48 million.

These data are similar to data derived from previous studies
(19). They suggest that for society as a whole, vaccination of college students is unlikely to be
cost-effective (Scott et al, unpublished data).

RECOMMENDATIONS FOR USE OF MENINGOCOCCAL POLYSACCHARIDE VACCINE IN COLLEGE STUDENTS

College freshmen, particularly those who live in dormitories, are at modestly
increased risk for meningococcal disease relative to other persons their age.
Vaccination with the currently available quadrivalent meningococcal polysaccharide vaccine
will decrease the risk for meningococcal disease among such persons. Vaccination
does not eliminate risk because a) the vaccine confers no protection against serogroup
B disease and b) although the vaccine is highly effective against serogroups C, Y,
W-135, and A, efficacy is <100%.

The risk for meningococcal disease among college students is low; therefore,
vaccination of all college students, all freshmen, or only freshmen who live in dormitories
or residence halls is not likely to be cost-effective for society as a whole. Thus, ACIP
is issuing the following recommendations regarding the use of meningococcal
polysaccharide vaccines for college students.

Providers of medical care to incoming and current college freshmen,
particularly those who plan to or already live in dormitories and residence halls,
should, during routine medical care, inform these students and their parents
about meningococcal disease and the benefits of vaccination. ACIP does
not recommend that the level of increased risk among freshmen warrants
any specific changes in living situations for freshmen.

College freshmen who want to reduce their risk for meningococcal disease
should either be administered vaccine (by a doctor's office or student health service)
or directed to a site where vaccine is available.

The risk for meningococcal disease among non-freshmen college students is
similar to that for the general population. However, the vaccine is safe and
efficacious and therefore can be provided to non-freshmen undergraduates who want
to reduce their risk for meningococcal disease.

Colleges should inform incoming and/or current freshmen, particularly those
who plan to live or already live in dormitories or residence halls, about
meningococcal disease and the availability of a safe and effective vaccine.

Public health agencies should provide colleges and health-care providers
with information about meningococcal disease and the vaccine as well as
information regarding how to obtain vaccine.

Additional Considerations about Vaccination of
College Students

Although the need for revaccination of older children has not been
determined, antibody levels decline rapidly over 2--3 years
(6). Revaccination may be considered for freshmen who were vaccinated more than 3--5 years earlier
(5). Routine revaccination of college students who were vaccinated as freshmen is not indicated.

College students who are at higher risk for meningococcal disease because of
a) underlying immune deficiencies or b) travel to countries in which
N. meningitidis is hyperendemic or epidemic (i.e., the meningitis belt of sub-Saharan Africa) should
be vaccinated (6). College students who are employed as research, industrial, and
clinical laboratory personnel who are routinely exposed to
N. meningitidis in solutions that may be aerosolized should be considered for vaccination
(6).

No data are available regarding whether other closed civilian populations with
characteristics similar to college freshman living in dormitories (e.g., preparatory
school students) are at the same increased risk for disease. Prevention efforts should focus
on groups in whom higher risk has been documented.

CONCLUSIONS

College freshmen, especially those who live in dormitories, are at a modestly
increased risk for meningococcal disease compared with other persons of the same
age, and vaccination with the currently available quadrivalent meningococcal
polysaccharide vaccine will decrease their risk for meningococcal disease. Continued
surveillance is necessary to evaluate the impact of these recommendations, which have
already prompted many universities and clinicians to offer vaccine to college freshmen.

Consultation on the use of these recommendations or other issues regarding
meningococcal disease is available from the Meningitis and Special Pathogens Branch,
Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases,
CDC (telephone: [404] 639-3158).

Acknowledgement

The following persons are acknowledged for their contributions to the economics section
of this report: Martin I. Meltzer, Ph.D. and R. Douglas Scott, II, Ph.D.

CDC. Control and prevention of meningococcal disease and Meningococcal disease
and college students: recommendations of the Advisory Committee on Immunization
Practices (ACIP). MMWR 2000;49(No. RR-7):1--22.

CDC. Control and prevention of meningococcal disease and Control and prevention
of serogroup C meningococcal disease: evaluation and management of suspected
outbreaks--- recommendations of the Advisory Committee on Immunization Practices (ACIP).
MMWR 1997;46(No. RR-5):1--21.

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